A convicted loyalist killer attempted to break into the Northern Ireland assembly chamber to slit the throats of Gerry Adams and Martin McGuinness because he "couldn't handle" Republicans being in government, a court heard today.

Michael Stone, 53, attempted to storm the building in order to kill both the Sinn Fein president and his colleague on November 2006, the day Mr McGuinness was designated Deputy First Minister.

However, Belfast Crown Court heard that his plan ended in failure when he was detained by security staff at the entrance to the building.

Mr Stone faces a total of 14 charges, including attempting to murder Mr Adams and Mr McGuinness. As well as the attempted murder charges, he is accused of possessing home-made explosives and an imitation gun with intent.

He is also charged with carrying a garrotte, three knives and an axe, and with assaulting staff members who trapped him in the revolving doors at Stormont.

Mr Stone has since denied the charges, claiming his attack was "performance art".

Charles Adair QC, prosecuting, said that after being arrested by police, Mr Stone said: "My intention was to walk into the debating chamber and look for where Adams, McGuinness and Sinn Fein were sitting. I would have lobbed several nail bombs to cause confusion.

"I planned to stab Adams and McGuinness and cut their throats."

Mr Adair said Mr Stone had claimed he would use "close-quarter tactics" to slit the throats of Mr Adams and Mr McGuinness.

The lawyer said Mr Stone explained to police why he had planned the assassinations. He told them: "I see Adams and McGuinness as Republican war criminals. Adams and McGuinness don’t deserve to be in a devolved Government. It would be a bastardisation of democracy".

After his detention and arrest, Mr Stone was taken by police from Stormont to the nearby Ulster hospital for a check-up because he had been complaining of chest pains and difficulty in breathing.

It was during the journey to the hospital that the prosecution claimed he told officers why he had launched the attack, saying of the prospect of Republicans being in Government: "I just can’t handle it."

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